Carroll Gardens was settled in the 19th century by immigrants from Ireland,[1] followed in the middle of the century by Norwegian immigrants,[8] who founded two churches, the Norwegian Seaman's Church (formerly the Westminster Presbyterian Church), now apartments, and the Norwegian Methodist Episcopal Church (formerly the Carroll Park Methodist Episcopal Church, no longer extant.[9]

The development of the South Brooklyn area, including Carroll Gardens, was aided by the foundation in 1846 by philanthropists Henry Pierrepont and Jacob E. Leroy of the Hamilton Avenue Ferry. Its purpose was to improve transportation to the newly created Green-Wood Cemetery, but horse car service, and later trolley lines, connecting to the ferry ran through Carroll Gardens, enabling businessmen who lived there to more easily commute to work in Manhattan.[5]

Houses with large front gardens on Second Place, laid out in 1846 by surveyor Richard Butt

In the late 1840s, Carroll Park, Brooklyn's third-oldest, a block-long area of playgrounds, walkways and sitting areas between Court, Smith, Carroll, and President Streets was built. Originally a private garden, it was purchased by the city in 1853, and was named after Charles Carroll in honor of his Maryland regiment, which had helped to defend the area during the Battle of Long Island in the American Revolutionary War.[6][5][10]

In 1846, surveyor Richard Butt planned gardens in front of the brownstone houses in the oldest section of the neighborhood when he developed it.[2] The homes are set further back from the street than is common in Brooklyn, and the large gardens became an iconic depiction of the neighborhood. The same year, a law was passed requiring that all buildings between Henry Street and Smith Street have 33 feet 5.25 inches (10.192m) between the building and the street for "courtyards."[11] The large gardens can be seen from First to Fourth Place between Henry and Smith Streets, as well as on President, Carroll and Second Streets between Smith and Hoyt Streets.[1]

Further development of the Carroll Gardens was aided by the draining in the late 1860s of the swampland which surrounded Gowanus Creek through the deepening and dredging of the Creek to create the Gowanus Canal. This provoked land speculation and a building boom throughout the area. It was during this period, from the late 1860s to the early 1880s, that the area which is now the Carroll Gardens Historic District began to be developed.[5]

Italian immigrants began coming to the neighborhood in the late 19th century – dock workers and workers in the Brooklyn Navy Yard[2] – continuing through the 1950s, which led to much of the Irish population of the area leaving beginning in the 1920s.[1] The rise of the Italian population provoked questions about the role of the Mafia in the neighborhood. One theory has it that Carroll Gardens, which lies between a territory traditionally controlled by the Gambino crime family and one controlled by the Colombo family, is considered to be neutral territory, and has been, for the most part, left alone.[2]

Apartment building on Third Place, dates from c.1875...

...and one on Second Place from 1965

Carroll Gardens had long been considered to be part of either the larger area referred to as South Brooklyn, or the neighborhood known as Red Hook. That neighborhood had an informal division in the 1930s and 40s along Hamilton Avenue, with kids from south of the avenue calling themselves "Hookers" after Red Hook, and kids north of the street in what would now be Carroll Gardens called "Creekers" after the now-drained Gowanus Creek.[2] This division became formalized beginning in the late 1940s by the building of the Brooklyn-Queens Expressway and the Gowanus Expressway, which started the process of the Carroll Gardens area taking on a separate and distinct character of its own. Still, it took a generation for that identity to be reflected in a distinctive name for the neighborhood; "Carroll Gardens" was named in the 1960s.[2] Today, Carroll Gardens is more middle class, while Red Hook, which had retained its working-class, waterfront ambiance, has only recently begun to feel the effects of gentrification.[12]

In the 1960s, young middle-class professionals began to be attracted to the Carroll Garden area due to its convenience to Manhattan, where many of them worked, and its growing reputation as a safe and quiet place to live. This began the gentrification of the neighborhood, and a response from older residents, who did not appreciate these "hippie" newcomers who had no ties to the community. Still, the Carroll Gardens Association was formed in 1964, and the decades-long control by a political machine was ended.[1][2]

Carroll Gardens has seen some French immigration since the late 1990s, and Bastille Day celebrations are held on July 14 of each year.[13][14] One of the public schools in Carroll Gardens, the Carroll School, has one of the area's few French dual-language programs.[15][16]

Though still visible in local business and culture, the Italian segment of the community has decreased significantly from 52 percent of the population to 22 percent in 2012.[17] Still, despite the decline in the Italian segment of the population and the effects of gentrification, the neighborhood remains a strongly Italian one, with games of bocce frequently seen, several dialects of Italian heard, and many Italian restaurants and shops, as well as fraternal and benevolent associations attached to specific towns in Italy.[1] The Roman Catholicism of the Italian population is still evident in the many shrines, especially to the Virgin Mary, which can be seen in front gardens in the neighborhood, and the tradition of a procession celebrating Good Friday continues.[2] Adult children who had moved away from Carroll Gardens have started returning to the neighborhood to raise their children.[2]

The development of what is now the Carroll Gardens Historic District began in the 1870s, due in part to its proximity to Carroll Park. The district was created by the New York City Landmarks Preservation Commission in 1973. It includes houses located in a rough rectangle bounded by Carroll, President, Smith, and Hoyt Streets, as well as the western ends of the two blocks between President Street and First Street. The district includes some of the finest examples of brownstones with large front gardens.[5]

The South Congregational Church Complex included the Early Romanesque Revival Church and Chapel at 358-366 Court Street, built in 1851 (chapel) and 1857 (church); the neo-Gothic Rectory at 255 President Street, built in 1893 and designed by Woodruff Leeming; and the Ladies Parlor at 257 President Street, built in 1889 and designed by F. Carles Merry in the Romanesque Revival style. At one time the chapel became the Calvary Baptist Church of Red Hook. All of the buildings have been converted to condominium apartments. The complex in a New York City landmark, designated in 1982.[9][2][18]

The Sacred Hearts of Jesus and Mary and St. Stephen's Church at Summit and Hicks Streets, was built c.1860 as St. Stephen's Church; the parish's name changed when it merged with another which lost its church in 1941 due to the building of the Brooklyn Queens Expressway. This church was designed by Patrick Charles Keely in the Gothic Revival style.[9][2][20]

The Westminster Presbyterian Church at 450 Clinton Avenue at First Place was built c.1865 in the Romanesque Revival style. It became Den Norske Sjomannskirke (the Norwegian Seaman's Church), founded by Norwegian immigrants; it was once visited by the King of Norway during an official visit to the United States. The church has now been converted to condominium apartments.[9][2][8]

St. Mary's Star of the Sea Church, located at 471 Court Street between Luquer and Nelson Streets was built in 1853 and was designed by Patrick Charles Keely. Originally constructed to serve as a cathedral, the church was built with Italian and European stones and marble. The church was where Al Capone married Mae Josephine Coughlin. A rectory and a girl's school – now the International School of Brooklyn – are also part of the church complex.[9][2][21][22][2]

Dennett Place is a short mews of residences running between Luquer and Nelson Streets in the block between Court and Smith Streets.[9]

The New York City Department of Education operates a number of public schools in the neighborhood: Patrick F. Daly (P.S. 15), John M. Harrigan (P.S. 29), Carroll School (P.S. 58), Samuel Mills Sprole (P.S. 32), the Brooklyn New School (P.S. 146), Brooklyn School of Collaborative Studies (M.S. 448), and the School for Innovation (M.S. 442).

Also in the area are the New Dawn Charter High School, the Mary McDowell Friends Middle School, and St. Mary's School.

The Brooklyn Public Library operates the Carroll Gardens Branch at 396 Clinton Street and Union Street in Carroll Gardens. The library, originally the Carroll Park Branch, opened in 1901 in a rented facility. The library moved to its current Carnegie library facility, designed by William B. Tubby, in 1905. After extensive renovations, the library received its current name in response to a request from the community.[23]